The formation of the Iberian Peninsula was completed following what is called 'the most important process in the geological history of southern Europe', in other words, an Alpine-Himalayan tectonic movement, which occurred in the Tertiary era.

Almost the entire morphology of mainland Spain was formed in the Tertiary era. The Pyrenees, the Andalusian, Cantabrian, Iberian and Sierra Morena mountain ranges, as well as the sedimentary basins of the Ebro and the Guadalquivir rivers were formed. The uplifting occurred by means of faults in the Galician massif, defining the Central Mountains and the Toledo mountains, and therefore, the unevenness that exists between the two plateaux. The marks left by these tectonic movements have fundamentally remained until present day. It can therefore be said that they gave rise to the geography of the peninsula as it is known today.